A HOLE in the ozone layer has appeared above Canada and Northern Europe for the first time, increasing the risk of skin cancer and severe sunburn.

Scientists say the ozone loss over the Arctic this year was so severe that it mirrored the famous ozone hole in the Antarctic.

Russia is also at risk.

Experts say the hole is not due to increased CFC release but temperatures at high-altitude making the existing chemicals 'more active'.

The paper, published in science journal, Nature, said, 'Chemical ozone destruction over the Arctic in early 2011 was—for the first time on record—comparable to that in the Antarctic ozone hole.'

This year's loss was predicted earlier this year by the World Meteorological Organization, who wrote, 'Depletion of the ozone... has reached an unprecedented level over the Arctic because of the continuing presence of ozone-depleting substances in the atmosphere and a very cold winter in the stratosphere.'

And it could get worse.

Chlorine compounds such as CFCs have been phased out in most countries but they remain in the upper atmosphere for decades.